Extrapolating what Nikon has achieved with the new 35/1.8G and the 50/1.8G I'd assume the 85/1.8G to be very sharp and contrasty. Below are the MTF-charts for the 85/1.8G left/1st and the 85/1.4G right/2nd:

On the x-axis is the distance from the image center (in mm). So left (=0) is center perfromance, right (=22mm) is performance in the corner of the sensor.
On the y-axis you can see the "relative" contrast: a value of 1 indicating that the lens does not deteriorate the contrast of the target, a value of 0.5 indicating that you'Re losing 1 stop fo contrast, 0.25 = 2 stops etc.
Now the red line(s9 show the contrast at a frequency of 10 line-pairs per mm, the blue-line(s) at 30 line-pairs per mm. For comparison: a D7000 (and the rumored D800) sensor could resolve around 100 LP/mm.
Normally you interpret the 10 LP/mm line(s) as contrast in general and the 30 LP/mm line(s) as micro-contrast or sharpness.
Just keep in mind that the diagrams show performance wide open only, so f1.8 performance for the new lens and f1.4 performance for the larger brother. If Nikon would show us the MTF-charts for smaller apertures the blue and red lines would climb towards 1, which is pretty boring